Understanding Your Colonoscopy Report

A colonoscopy is one of the most effective ways to determine the presence of cancerous tumors or precancerous polyps as it allows doctors and specialists to directly survey the inner lining of the colon and rectum.

Following the procedure, a report containing the details of the polyps and/or tumors identified, where they were found and if they were removed during the colonoscopy is provided.

While your doctor will explain the outcome of your colonoscopy procedure to you, it is also a good idea to have some understanding of the possible results you might receive.

Amongst other details, your colonoscopy report will include the number of polyps found, what they look like and how big or small they are.

The morphology — or form and structure — of a lesion can be described as a polypoid that protrudes from the mucosal lining or a non-polypoid that has flat or depressed structures. In general, polyps that form are either pedunculated or sessile, where they appear attached to the lining to a stalk (pedunculated, or resembling a cherry or mushroom) or have a dome shape that lies flat against the wall of the intestine (sessile).

Sessile polyps make up about 85% of all polyps found, and together with pedunculated polyps are typically easy to remove during a colonoscopy. Any polyp removals are also included in the report, along with the method of removal used.

On the other hand, non-polypoid lesions make up about 2% of discovered lesions and can be flat and elevated, completely flat, superficially depressed or excavated/ulcerated. At times, some non-polypoid lesions may also appear flat and elevated with a central depression.

While flat polyps are less common, they are also difficult to locate and harder to remove compared to pedunculated or sessile polyps. These flat polyps often grow laterally instead of in height (relative to the colonic lining). Due to the difficulty in detecting them, flat polyps are believed to be responsible for colorectal cancers in individuals who have regular screening colonoscopies.

Besides the appearance of a polyp, where on the colon the polyp is found is also documented, such as if the polyp was found in the ascending, transverse, descending, sigmoid colon, or in the rectum. This is also accompanied by a diagram of the colon with areas where the polyps are found marked.

While not always the case, doctors may be able to immediately identify benign or malignant polyps by considering the following factors:

• Size of the polyp: Large polyps 10 mm or larger in diameter are considered to have a significant risk of developing into cancer.
• The growth pattern: Polyps may have tubular, villous or tubulovillous growth patterns. Villous growth patterns are indications of more chaotic and rapid cell growth.
• Vasculature, or the presence of blood vessels with the help of narrow band imaging (NBI): cancerous polyps typically have different vascular appearances from benign polyps. For instance, hyperplastic polyps may not have any prominent blood vessels, or may have regular, lace-like patterns. Cancerous growth, on the other hand, would show areas of disrupted or missing vessels. This is due an upregulation of vascular endothelial growth factor (VEGF) in tumor microenvironments that result in rapid but irregular growth of blood vessels.

In instances where it is not immediately perceivable, a follow-up pathology or biopsy report is required to determine if the cells found in any tissue samples or polyps removed are cancerous.

While the presence and location of polyps and/or tumors are usually the key takeaways, colonoscopies are not only conducted in the context of colorectal cancer, but also other gastrointestinal disorders.

Your colonoscopy report may include diverticula findings, where bulges or pockets are formed in the intestinal wall. Any hemorrhoids found will also be reported.

Depending on the hospital or clinic, the colonoscopy report may be accompanied by the pathology or biopsy report, which describes the characteristics of the tissue sample taken from the patient, including a microscopic description and if cancerous cells were found.